Various power inverters have been widely used in electronic circuits (such as power supplies, computers, household appliances, nuclear magnetic resonance gradient amplifiers, UPS uninterruptible power systems, solar inverters, converters, power amplifiers for a vibration test, frequency converter of 400 Hz, 800 Hz, 1200 Hz, etc.) to provide a stable constant voltage or constant current. Its function is that an input power type is converted into a required load power type. In general, a power inverter is composed of a power switch component (such as a power transistor, a power diode, etc.), an electrical energy storage, and a filter component (such as an inductor, a capacitor, a transformer, a choke coil, etc.), and a detection and control component.
Thereby, the voltage or current is adjusted (switched and rectified) by the detection and control component to control the power switch component. The electric energy storage and the filter component provide the required filtering and temporary electrical energy for converting the electric energy. However, during the power conversion, the power inverter converts part of the energy supplied from the power supply into heat energy. The heat energy is concentrated in the power transistor and the choke coil of the power inverter.
The demand for power inverters used for industrial and server applications is extremely large. The power inverters are mounted to a chassis through a rack. A general business gathers power inverters and servers in a computer room to facilitate the management. The power inverters and the servers are running all day long. Therefore, the heat dissipation of the power inverters is particularly important.
For the convenience of management and space saving, the casing for the rack-type power inverter usually adopts a common industrial standard, its width is fixed at 19 inches, height in U units (1 U=1.75 inches=44.45 mm). The standard casings are usually 1 U, 2 U, 3 U, and others. In general, at the same power, the power inverter composed of a power switch component, a power storage, and a filter component, and a detection and control component needs better heat dissipation conditions, so it is necessary to use a larger casing, such as a casing of 3 U or more.
However, in order to reduce the size of the casing, a casing of 2 U or less is developed accordingly. But its configuration design causes poor heat dissipation. The reason is that the power inverter has a plurality of choke coils and a plurality of power transistors. The choke coils are often horizontally arranged in the limited space, so the heat is concentrated at the bottoms of the choke coils. The power transistors and other electronic components are generally vertically arranged on the circuit board, which shields the wind blowing of the fan and cannot provide a smooth heat dissipation path. As a result, the heat is concentrated at the power transistors and the choke coils of the power inverter. The power inverter may stop running or fail or be damaged due to overheating.
Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.